You're not alone: Medical conspiracies believed by many

NEW YORK (Reuters Health) - About half of American adults
believe in at least one medical conspiracy theory, according to
new survey results.

Some conspiracy theories have much more traction than
others, however.

For example, three times as many people believe U.S.
regulators prevent people from getting natural cures as believe
that a U.S. spy agency infected a large number of African
Americans with the human immunodeficiency virus (HIV).

J. Eric Oliver, the study's lead author from University of
Chicago, said people may believe in conspiracy theories because
they're easier to understand than complex medical information.

"Science in general - medicine in particular - is
complicated and cognitively challenging because you have to
carry around a lot of uncertainty," Oliver said.

"To talk about epidemiology and probability theories is
difficult to understand as opposed to 'if you put this substance
in your body, it's going to be bad,'" he said.

For the new study, he and his colleague used data from 1,351
adults who answered an online survey between August and
September 2013. The data were then weighted to represent the U.S
population.

The participants read six popular medical conspiracy
theories and then indicated whether they had heard of them and
whether they agreed or disagreed with them.

Like the theories about conspiracies to infect African
Americans with HIV and to prevent citizens from accessing
alternative medicines, the other theories on the list had
mistrust of government and large organizations as themes.

They include the theory that the government knows cell
phones cause cancer but does nothing about it, that genetically
modified organisms are being used to shrink the world's
population, that routine vaccinations cause autism and that
water fluoridation is a way for companies to dump dangerous
chemicals into the environment.

Some 49 percent of the survey participants agreed with at
least one of the conspiracies.

In fact, in addition to the 37 percent of respondents who
fully agreed that U.S. regulators are suppressing access to
natural cures, less than a third were willing to say they
actively disagreed with the theory.

With regard to the theory that childhood vaccines cause
psychological disorders like autism and the government knows it,
69 percent had heard the idea, 20 percent agreed with it and 44
percent disagreed.

The only conspiracy theory with which more than half of the
respondents disagreed was that a U.S. spy agency infected a
large number of African Americans with HIV.

The survey results suggest people who believe in medical
conspiracy theories may approach their own health differently,
the researchers said.

For example, while 13 percent of people who did not believe
in any conspiracies took herbal supplements, 35 percent of those
who believed in three or more theories took supplements.

Overall, the researchers say people who believed in
conspiracies were more likely to use alternative medicine and to
avoid traditional medicine.

"Although it is common to disparage adherents of conspiracy
theories as a delusional fringe of paranoid cranks, our data
suggest that medical conspiracy theories are widely known,
broadly endorsed, and highly predictive of many common health
behaviors," the researchers write in JAMA Internal Medicine.

Oliver said the findings may have implications for doctors.

Instead of viewing patients who believe in conspiracy
theories as crazy, he said doctors should realize those patients
may be less likely to follow a prescription regimen.

"It's important to increase information about health and
science to the public," he said. "I think scientific thinking is
not a very intuitive way to see the world. For people who don't
have a lot of education, it's relatively easy to reject the
scientific way of thinking about things."